SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3571ffa9a415718a1eaf0212846d4bc1279dacb84c30195a33d889fba8254a80' 
  AND token = '3UV3qgCpPTeFx5JBiBiL2pehGGq+3p4T/2jVXMJ6tFY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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