SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '410125edac35093af1e24d85f5eb49207b43f531f6d9be2082bf39d60a062f83' 
  AND token = 'ELag0m+WcykkyBlHVMoFOjgU5SVH0x0+vbT/ntSljc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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