SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de2349804f5b7e51184c011cb0111ce69337a735d76e7ccd3a2604e91ce45459' 
  AND token = 'Bhtfx4U0AkzTHZi53IDQzZdcJZtFmBGSF34XTEpSpr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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