SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'febb986551dd69aeaf84f2257581115c6098a50dbbaea27cfb0e139358ef3147' 
  AND token = 'DSvM+CJIzEoSoHsv0DApaF03AoOpFpI3chLMyNjZqIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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