SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd90dcadef0d026ab07092c209b2233d0e63649712cf18494409e102aac998cc1' 
  AND token = 'McoEsCAOBcT5n3Pa5r5jrrxxz6vOpAVSt2DqMBTPXWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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