SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d5d4fdd7ff24de0f936e23fdf11f33bb92701a783c5bc23a234d75282b47b5a' 
  AND token = 'pz6LnGbfqH+zAh4jfYCM8tsmpgqPBhbixVIvHFmok6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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