SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5984cad6ab9d247aeebfbecd8bfc5c8054fc28c1f6084e3e61f40ae745babae' 
  AND token = 'PyNpPPqBp3FaaLuYMKu6tXI8RuHdbfiPU/UYM29Sm2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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