SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5389d43ab5c75b3623208a1fe352492fb0dd31cd016cfcc06c6e911b6285ddc6' 
  AND token = 'uIKk/LaaUG+Dl9P847dkCv1q4jV+vPLYJl+JWJJpjpE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}