SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5d344990223ea3c86e5fdbe0b39ffb7402fead8e0b1749b6809ee8c2a855dc0' 
  AND token = 'I4s8lhXWyDTaHH3104ZICL99JWYcCc2ZBvIdnKOT0CA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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