SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '23a8fdb155bfa393cc02fd6e7c7ba4fc832b7cedb9d10e19927d19e637df19b1' 
  AND token = 'mdSnj6DJyhoqYZzbqDCnGnFuVPaS9CLgeoOUHg8GLTI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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