SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2858f2d023d1f37ec5321a2b1f4794feb7f0e95b0e861a3e3128225b25d3fe8f' 
  AND token = '/SN5iYCaANSsU60memH0VMjL5gxFfgoRtsUzBBaD2PY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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