SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '215cfa592fc442ef38f41fb22a47ecb0921e451f99228d1972100e5b009b5cd2' 
  AND token = 'ddhsD+SICqPvLa/92pHR3Ix64idjmeUgISpJZtZ4CoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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